Automatic violin-player.



Li M. LAWTON.

- AUTOMATIC VIOLIN PLAYER.

APPLICATION FILED MAR ZI, 1915- 1,266,028. Patented May 14, 1918.

5 SHEETS-SHEET I.

I07 o O? a 67 A? 2 47 i F 56 58 L.M.LHWTON L..M. LAWTON.

AUTOMATIC VIOLIN PLAYER. APPLICATION FILED MAR. 27. 1915'.

.1 ,266,028. Patented May 14,1918.

5 SHEETS-SHEETZ- L. M. LAWTON.

AUTOMATIC VIOLIN PLAYER.

. APPLICATION FILED MMLZZ, 1915.

1,266,028. Patented Mayl l, 1918.

5 SHEETS-SHEET 3.

L. M. LAWTON. AUTOMATIC VIOLIN PLAYER.

APPLICATION FILED MAR.27| I915.

Pdtgnted May 14, 1918.

5 SHEETSSHEET 4.

N 0, T W H L w I .3. nOuW LEIDRA M. LAWTON, or NORTH COLLINS, new YORK.

AUTOMATIC VIOLIN-PLAYER.

Specification of Letters Patent.

Patented May 14, 1918.

Application filed March 27, 1915. Serial No. 17,461.

To all whom it may concern:

Be it known that I, LEDRA M. LAWTON, a citizen of the United States, residing at North Collins, in the county of Erie and State of New York, have invented certain new and useful Improvements in Automatic Violin-Players, of which the following is a specification, reference being had to the accompanying drawings.

This invention relates to an improved automatic violin player, and has for its primary object to provide music sheet actuated pneumatically controlled means for operating a plurality of violin bows.

It is an additional object of my invention to provide improved means for alternately moving the bows in opposite directions by air pressure and suction, and means for controlling the operation of said latter means including mechanical elements movably mounted upon a tracker board and engaged and actuated by a perforated music sheet in its passage over said board.

The invention has for an additional object to provide vacuum-actuated fingering means also controlled by the music-sheet in its passage over the tracker board.

It is a further general object of my invention to provide a pneumatically operated violin player which is positive and reliable in practical operation, and comparatively simple and inexpensive in its construction.

With the above and other objects in view, my invention consists in the novel features of construction, combination, and arrangement of parts to be hereinafter more fully described, claimed, and illustrated in the accompanying drawings, in which,

Figure 1 is an elevation with the front wall of the casing or cabinet removed;

Fig. 2 is a side elevation;

Fig. 3 is a section taken on the line 3-3 of Fig. 1, certain of the parts being broken away; I

Fig. 4 is an enlarged vertical section through one of the bow operating mechanisms;

Fig. 5 is a horizontal section taken on the line 5-5 of Fig. l;

Fig. 6 is an enlarged detail elevation illustrating the mounting and operating means for the string-engaging fingers;

Fig. 7 is a detail view illustrating the mounting of the music rolls and the tracker board;

Fig. 8 is a detail view of a fragment of the perforated music sheet, showing perforations for controlling the operation of the bows and the string-engaging fingers, respectively.

Fig. 9 is a detail transverse section through the tracker board;

Fig. 10 is a fragmentary longitudinal section through the tracker board.

Fig. 11 is a vertical sectional view through one of the bow operating mechanisms taken at right angles to Fig. l. 1

Referring in detail to the drawings, 5 designates a suitable case or cabinet which is preferably mounted upon corner support ing legs 6 and is, of course, provided in its front wall w ith one or more doors to admit of access to the interior of the "case. The case 5 is divided into upper and lower compartments or chambers by a horizontal division wall 7.

In the lower chamber of the cabinet, and in the rear end at one side thereof, an air pressure receiving tank 8 is arranged, and in the opposite corner of the chamber, the vacuum tank 9 is mounted. 10 designates a series of pressure pumps for supplying air under pressure to the tank 8, and 11 indicates a series of vacuum pumpsfor maintaining the vacuum within the tank 9. These pumps are, of course, connected to the respective tanks by pipes or tubes, indicated at 12 and 13, respectively, and are actuated from a common shaft 14;. The ends of this shaft are journaled in suitable bearings 15 secured upon the side walls of the case 5, and the pump pistons are actuated through the medium of two series of eccentrics 16 and 17, respectively, which are secured upon said shaft. The intermediate portion of the shaft 1 1 is formed with spaced oppositely extending crank 18, and rods19 connect these cranks to the pedal members 20 which are fulcrumed as at 21, upon the base or bottom wall of the cabinet 5. A fly wheel 22 is also secured upon the shaft 14: and upon opposite sides of the intermediate portion of the shaft, the belt wheels 23 are fixed thereon. The purpose of these wheels will be hereinafter referred to.

In the upper chamber or compartment of the case 5, a horizontally disposed beam 24: is arranged and fixed at its ends to the side walls of the case. This beam is also supported upon the division wall 7 by means of spaced posts or uprights 25. To one of the side walls of the case, one end of the tracker board 26 is hinged, the other end thereof being supported by the beam 24. The music sheet rolls 27 are arranged upon opposite sides of the tracker boardin spaced relation thereto and below the same, the trunnions on the ends of said rolls being mounted in suitable bearings on the side wall of the case and the beam 24. Below the horizontal partition wall 7, spaced axially alined shafts 28 are rotatably mounted, and upon each of these shafts, a belt wheel 29 is fixed. These wheels are traversed by the drive belts 30 which extend upwardly through the partition wall 7 and around similar belt wheels 31 which are fixed upon one trunnion of the respective rolls 27. Ad-

' ditional belt wheels 32 are also loosely ar ranged upon the shafts 28 and carry female clutch sections 33 which are adapted to be engaged by the male clutch sections 34 splined' upon the respective shafts. The wheels 32 are connected to the wheels 23 on the shaft 14 by the driving belts 35. The shiftable clutch members 84 are connected by a rod 36 to which a suitable handle is attached, whereby the clutch members may be simultaneously actuated and alternately moved into or out of locking engagement with the respective loosely mounted wheels 32. It will thus be understood that either of the rollers may be positively driven. 37 designates the perforated music sheet which will be hereinafter more particularly referred to, said sheet being provided with means upon its ends for attaching the same to the rolls. It is, of course, understood that one of the rolls 27 is removable from its bearings, so that the same may be replaced by another roll. The upper surface of the tracker board is slightly convex and the music sheet 37 passes over this convex surface from one roller to the other.

88 designates the violin body of any ordinary or approved construction and is mounted in the upper chamber or compartment of the cabinet 5, the end of the violin body being-held in a suitable clamp, as shown at 39, while the end of the neck rests upon a supporting bracket 40 fixed to one of the side walls of the case. The violin is provided with the customary number of strings and a corresponding number of bows, indicated at 41, are provided for engagement upon the respective strings. Each bow is formed with a longitudinal arm or extension 42 havin rack teeth 43 on its lower ,side. These rack teeth engage a pinion 44 fixed upon one end of a shaft 45 which is mounted in supporting standards 46 secured to the partition wall 7. A pair of vertically disposed cylinders 47 are also arranged upon each side of the violin within the upper chamber of the case, said cylinders being provided with suitable standards fixed upon the partition wall 7. A vertically movable valve member 48 is arranged in each of the cylinders and is provided with a rod 49 which extends upwardly through an opening in the top wall of the cylinder. The cylinder 47 is provided at diametrically opposite points with ports 50, one of which communicates with the interior of a laterally extending cylinder 51 which is suitably secured at one of its ends upon the wall of thecylinder 47. A piston 52 is longitudinally movable in the cylinder 51 and is provided with a rod 53 movable through an opening in the outer end of said cylinder. This rod has rack teeth 54 formed upon its upper edge for engagement with the pinion 55 which is secured to the end of the shaft 45. Upon the opposite side of the cylinder 47, the head 56 is suitably mounted, said head being provided with spaced ports 57 opening upon the outer face thereof, said ports at their inner ends merging into each other and registering with one of the ports 50 in the wall of the cylinder 47. In the head 56, a longitudinally sliding valve plate '58 is arranged to traverse the ports 57, said plate being provided with spaced openings 59 to register with the respective ports in the manner to be hereinafter pointed out.

The valve member 48 is provided with a diametrically extending opening 60, the ends of which are normally in registering relation with the connected ends of the ports 57 and the interior of the piston cylinder 51. The valve member 48 is also provided with a second opening 61 therethrougn, a portion of which extends in parallel relation to the opening 60 and opens upon the periphery of the member 48 at one of its ends in line with the corresponding end of said opening 60. From the center of the member 48, this latter port or opening 61 therein is obliquely extended, as shown at 62, so that the other open end thereof is laterally spaced from the corresponding end of the opening 60 in the valve member. The cylinder 47 is provided with an exhaust port 63 with which the outer end of this obliquely disposed portion 62 of the opening through the valve member is adapted, in one position of said valve, to register. The valve member 48 is normally held yieldingly against an upward vertical movement within the cylinder by means of a coil spring 64 which is secured to the base of the cylinder and to the bottom of said valve member. l Vith one of the ports 57 in the head block 56, a pipe 65, extending from the vacuum tank, is connected, and a pipe 66 extending from the pressure tank is connected to the other of said ports. These pipes are alternately placed in communication with the laterally projecting cylinder 51 through the medium of the slide valve 58 and the vertically movable valve member &8, in the manner which will now be described.

In suitable bearing brackets 67, the shaft-s 68 are mounted, and each of said shafts is provided upon one end with a crank arm 69 which is engaged beneath a head formed upon the upper end of the valve rod L9. The other end of each shaft is also provided with an upwardly projecting arm 70 to which one end of a link 71 is pivotally connected. These rods for one pair of the valve members 48, are connected at their inner ends to levers 72 which are fulcrumed intermediate of their ends, as at 7 3, upon one of the vertical posts or uprights 25. The other ends of the levers 7 2 are connected by means of the links 7%, to the lower ends of the levers 75 which are mounted to oscillate upon a rod 76 secured in the tracker board 26. The levers 75 correspond in number to the number of bows ll. The other pair of bow controlling valve members &8, upon the opposite side of the violin, are actuated through the medium of links 77 which connect the arms 7 O of the rock shafts directly to the levers 75 in the tracker board, without the intermediate lever connections 72. The upper ends of the levers 75 project above the upper surface of the tracker board 26 and are slightly curved in a direction opposite to the direction of movement of the perforated music sheet 37.

Each of the valve members a8 is provided at its lower end and upon diametrically opposite sides, with grooves 78, 7 8. In these grooves, the inner ends of sliding pins 79 are normally engaged and yieldingly held by the leaf springs 80, said springs being fixed at one of their ends and having their free ends engaged with opposite sides of the A pair of toggle links 81 are pivotally connected to the outer end of each of the pins 79 at one of their ends and have their other ends connected to a second pair of links 82, the latter pair of links being pivotally connected to a link 88. To

pins 79.

a cross bar 84 fixed upon each of these links, one end of a pair of leaf springs 85 is secured. Intermediate of their ends, these springs are inwardly curved, as at 86, and have bearing engagement upon the joints between the toggle links 81 and 82. Coil springs 87 are also arranged between the connected ends of these toggle links and normally act to draw the same together and hold said links against spreading movement. The outer ends of the links 83 are connected to one end of the levers 88 which are fulcrumed, as at 89, upon suitable supports 90. The other ends of these levers In Fig. 8 of the drawings,

I have illuslongitudinally extendingv trated a fragment of the music sheet, and it will be understood that the same is provided with two separate and distinct longitudinally extending groups of elongated perforations. For convenience in distinguishing these two groups of perforations and for the purposes of this explanation, I have designated the same as bow controlling perforations and finger controlling perforations, respectively. It will be noted that the bow-controlling perforations are arranged in groups out of longitudinal alinement'with each other, there being four perforations in each group for the individual bows. In the illustration, the perforations are arranged in necessary relation for the scale, and one of the perforations for controlling the bow operating upon the D string is of greater length than the others, so as to hold or prolong the tone without a break in the continuity thereof. In the operation of the bows, as the music sheet moves over the tracker board, one of the levers 75 will project through one of the perforations, and the spring 64L is thus permitted to act and draw the valve member 18 downwardly so as to dispose the opening 60 therethrough in registration with the inner connected ends of the ports 57. The one of these ports which is connected to the vacuum tank, is closed by the valve plate 58, but the other of said ports is opened through the valve plate so that air under pressure from the tank 8 may enter through the port 60 in the valve member and into the cylinder 51. The piston 52 in said cylinder is thus forced outwardly and the rack 54. cooperating with the pinion 55 rotates the shaft The pinion n on the other end of this shaft, engaging the rack 43, draws the bow 11 downwardly across the string of the violin. In the continued movement of the music sheet 37 for a distance equivalent to the length of the perforation through .which the lever 75 extends, this downward movement of the bow continues until the music sheet at the end of the perforation finally strikes the upper end of the lever 75 and rocks the same upon the bar .haust passage 61 therethrough' in communication with said cylinder. The air in this cylinder. is thus exhausted through said passage and the port 63 to the atmosphere. In the upward movement of the valve member 4:8, one of the sliding pins 79 is projected into the groove 78 in the periphery of said valve member by the springs 80, and the leaf springs 85 acting against the toggle link connections 81 and 82, in conjunction with the springs 87, hold said links against a spreading movement. When the lever '{5 enters the next perforation in the muslc sheet, the spring 6% again acts to draw the valve member 4:8 downwardly so that the pin 7 9 is forced out of the groove 78. As shown in Fig. 5, the leaf springs 85, together with the coil springs 87 acting upon the toggle links 81, 82 prevent spreading thereof, and therefore, as the pin 7 9 is forced out of the groove 78 in the valve member, the connection 83 between the toggle links on one side and one of the levers 88 will exert a pressure on the end of said lever and the other end thereof being connected to the valve plate 58 will slide said plate. The two levers 88 being attached to the ends of the valve plate are always the same distance apart so that they will at all times be in parallel relation to each other. Thus, as indicated at the upper side of Fig. .5, when the plate has been shifted to the position shown, the connection 83 between the toggle links and the end of the lever 88 is forced inwardly to spread the links, this inward movement being equivalent to the depth of the groove 78. The toggle links bear against the leaf springs 85 and force the same apart and also expand the spring 87. The extremities of the springs 85 being forced apart, permit the pin 7 9 to enter between the same. When the valve plate 58 is again drawn upwardly, the small leaf springs 80, (referring to the upper side of Fig. 5) will force the pin 7 9 into the groove 78 and thus permit the toggle links to close, the ends of the springs 85 engaging upon the end of the pin 79 in position for the next operation, the parts being arranged precisely as shown at the lower side of Fig. 5. it will be understood that the pins 7 9 alternately enter the respective grooves in the valve member when the same is drawn up ardly, and these pins are not both engaged in the grooves at the same time. As the pin in the groove of the valve is forced outwar ly in the downward movement of said valve, the toggle links and springs 85 being in the positions shown at the lower side .of Fig. 5, constitute a rigid connection between the pin and the lever 88 so that the valve plate will be moved in one direction. In order to permit of such movement, it will be understood that the toggle links connected to the other of the pins 7 9 are spread apart against the action of the springs 85. Thus, in the next upward movement of the valve member, the springs 85 and 87 will close the toggle of this pin 79 and the springs 80 will force said pin into the groove on one side of the valve member. The toggle links 81 and 82 at the opposite side of the valve, as shown in Fig. 5, are folded or drawn together by means of the springs 87 and 85 so that the pin 7 9 cannot be forced inwardly by the springs 80 and this pin will not engage in the groove 78. Therefore, in the next downward movement of the valve, the pin shown at the upper side of Fig. 5, which is engaged in the groove 78, will be forced outwardly and through the medium of the toggle links and the connections 83 and 88, the valve plate 58 will be shifted in the opposite direction to that above referred to, whereupon the toggle links at the lower side of Fig. 5 will be spread apart so that in the next upward movement of the valve 48, the other pin 79 is forced into a groove 78 by the springs 80. l When the valve is again forced downwardly, the operation is reversed and the valve plate 58 moved in the opposite direction to register one of the openings 59 with the pipe 66. The arrangement of the connections between the levers 88 and the pins 7 9 on opposite sides of the valve, as shown in Fig. 5, will, therefore, be just reversed. This operation is repeated continuously during the operation of the machine.

Thus, each of the bows is alternately moved back and forth across the violin string and the extent of such movement and the relative times of movement of the several bows is entirely controlled and determined by the relative arrangement or disposition of the several sets of perforations in the music sheet.

In order to change the pitch, pneumatically controlled string engaging fingers are employed.

l-teferring now in detail to Fig. 6 of the drawings, it vnil be observed that each of the finger-operating mechanisms includes a lever 91 which is fulcrumed upon a suitable support, as at One end of each lever is normally disposed in a horizontal position and extends inwardly from its pivot over the violin keyboard. The inner extremity of each lever has a relatively heavy stringengaging finger 93 secured thereto, and to each of the levers 91 a coil spring 94; is

connected which normally acts to yieldingly, but firmly, hold the finger in engagement with one of the strings. In the arrangement of the string engaging fingers, the fingers operating upon the A and E strings are arranged upon one side of the violin keyboard while the fingers to operate upon the D and G strings are disposed upon the opposite side of the keyboard. The outer end of each lever 91 is downwardly and outwardly extended from its pivot 92, as shown at 95, and upon the outer extremity of the lever, one end of a lever 96 is engaged. Tn suitable brackets or supports 97, the cylinders 98 are secured, and in each of said cylinders, a vertically movable piston 99 is disposed. The rods 100 of these pistons extend downwardly and are connected to the respective levers 96 at their outer ends, said levers being pivotally mounted, as at 96, adjacent to their opposite ends which bear upon the finger carrying leavers 95. To the upper end of each piston cylinder 99, one end of a tube 101 is connected, the other end of which extends through an opening 102 in the tracker board 26 and opens-upon the upper face of said board. Each of the cylinders 98 is connected bya pipe 103 to a pipe 104: which leads to the vacuum tank 9. Communica tion between the several cylinders and the tank through this latter pipe, is manually controlled by means of a valve indicated at 105 which is actuated by means of the rod 106 extending upwardly above the beam 2%, said rod being provided in its upper end with a suitable button or head. Referring now to the music-sheet shown in Fig. 8, it will be observed that there are four rows of perforations for each string, each per foration controlling one of the string engaging fingers. From the above description, the operation of this portion of the mechanism will be clearlyunderstood. As the music sheet passes over the tracker board, when one of the perforations in the sheet registers with the open end of one of the tubes 102 extending through the tracker board, the vacuum in the particular cylinder 99 to which said tube is connected is destroyed by opening communication between said cylinder and the atmosphere. It will be understood that the piston in said cylinder is normally held in a raised position by the vacuum created in the cylinder in the operation of the vacuum pumps, and the inner ends of the levers 96 thus exert a downward pressure upon the outer ends of the levers 95 and maintain the fingers 93 in an elevated position out of contact with the violin strings. As soon, however, as the vacuum is destroyed in each cylinder in the manner above stated, the piston therein immediately drops so that pressure upon the end of the lever 95 is relieved and the weighted finger members 93 are firmly drawn downwardly by the springs 9& upon the respective strings. Thus, the proper pitch, in accordance with the arrangement of the perforations in the music sheet, is obtained.

After the music sheet 37 has been C0111- pletely unwound from the right hand roller 27, shown in Fig. 1, the score thereon having been played in the manner above explained, the sheet is drawn across the tracker board and rewound upon the right hand roller. The several levers 75 mounted in the tracker board are moved to a noninterfering position below the upper surface of the tracker board, by means of levers 107 mounted upon the beam 24:. The lower ends of these levers are provided with the cross pins 108 for engagement with the upstanding arms of the respective pairs of rock shafts 68. It will thus be apparent that when the levers 107 are moved to the dotted line position shown in Fig. 1, the

levers in the tracker board are moved through the medium of the roads 7 4 and 77 to their inoperative positions. It is, of course, understood that when the music sheet is to be re-rolled after placing the levers 75 in an inoperative position by means of the levers 107, the rod 106 is also depressed to close the valve 105 in the pipe connection between the vacuum tank and the several cylinders 99. The clutch members 34 are now shifted so as to release one of the shafts 28 but look the belt wheel 32 on the other of said shafts against independent movement so that rotation will be transmitted by the belt 35 to said shaft and then through the connecting belt 30 to the right hand roller 31. The movement of the music sheet will thus be reversed across the face of the tracker board and said sheet rewound upon the latter roller which may then be removed from its bearings and a new roll inserted therein.

It will be readily appreciated that the same principle may be employed with such slight modifications as are deemed necessary, in adapting the invention for playing a mandolin, guitar, and analogous musical instruments. The case or cabinet of the machine will preferably be provided with a suitable cover, the front wall of the case having a number of openings therein through which the sound waves may issue. The entire apparatus, being housed within the case, is invisible, so that the instrument will present airattractive appearance. The number of bows and air controlled operating means therefor, may, of course, be increased in accordance with the number of strings provided on the instrument which is to be operated upon. My invention is also susceptible of various other modifications in the form, proportion, and arrangement of the several elements thereof, and it will, therefore, be'understood that I do not desire to be limited to the precise details of the parts but reserve the privilege of resorting to all such legitimate changes as may be fairly embodied within the spirit and scope of the invention as claimed.

Having thus fully described my invention, what I desire to claim and secure by Letters Patent is 1. The combination with a stringed musical instrument, of bows operating upon the respective strings of the instrument, a plurality of cylinders, individual operating mechanisms for the respective bows each including a reciprocable element mounted within one of the cylinders, air pressure and vacuum tanks, valves controlling communication between said tanks and the respective cylinders, an operating means for each of the sald valves, and means for selectlvely actuating said operating means, whereby the,

air is admitted to said cylinder and avacuum created therein alternately to move the reciprocable element in opposite directions and operate the respective bows.

2. The combination with a stringed musical instrument, of bows operating upon the respective strings of the instrument, a plurality of cylinders, individual operating means for the respective bows each including a reciprocable element mounted within one of the cylinders, air pressure and vacuum tanks, valves controlling communication between said tanks and the respective cylinders, an operating means for each of said valves, and a movable perforated web the perforations of which are adapted toreceive one element of each of the valve operating means and selectively actuate said valves to alternately admit air pressure to the cylinders and create a vacuum therein whereby the reciprocable element is moved in relatively opposite directions and the bows operated.

3. The combination with a stringed musical instrument, of bows operating upon the respective strings of the instrument, a plurality of cylinders, individual operating mechanisms for the respective bows .each including a reciprocable element mounted within one of the cylinders, air pressure and vacuum tanks, slide valves controlling communication between each of said cylinders and the tanks, means for actuating said valves to alternately admit air to the cylinders and create a vacuum therein, and means for selectively operating said last named means whereby the slide valves are actuated to effect the independent operation of the bows.

4. The combination with a stringed musical instrument, of bows operating upon the respective strings of the instrument, a plurality of cylinders, individual operating mechanisms for said bows each including a reciprocable element movable within one of the cylinders, air pressure and vacuum tanks, a vertically movable member to establish and out 01f communication between the respective tanks and the cylinder, a slide valve actuated by said member to alternately establish communication through said member between the respective tanks and the cylinder whereby said reciprocable element 1s moved in relatively opposite directions, and means for 'selectively actuating sald vertically movable members to efi'ect the independent operation of the bows.

5. The combination with a stringed musical instrument, of bows operating upon the respectlve strings of the instrument, a plurality of cylinders, individual operating mechanisms for said bows each including a reciprocable element mounted within one of the cylinders, air pressure and vacuum tanks, a vertically movable member provided with a port afi'ording communication between the tanks and the cylinder, a slide valve actuated by said member to alternately connect the tanks to the port in said member whereby the reciprocable element is moved in opposite directions, said vertical element being also provided with an additional port to establish communication between said cylinder and the atmosphere to release the air pressure therefrom prior to the creation of a vacuum, and means for se lectively actuating said vertically movable members to effect the independent operation of the bows.

6. The combination with a stringed musical instrument, of bows operating upon the respective strings of said instrument, a plurality of cylinders, individual operating mechanisms for said bows each including a reciprocable element mounted in one of the cylinders, air pressure and vacuum tanks, a spring held vertically movable member having a port to establish communication between said tanks and the cylinder, a slide valve actuated by said member to alternately open and close communication between the respective tanks and said cylinders through said port, operating means for each of said members including a pivoted element, and a movable web provided with means to selectively engage and actuate said pivoted elements and move the respective members whereby the reciprocable elements are actuated to operate said bows.

7. The combination with a stringed musical instrument, of bows operating upon the respective strings of said instrument, a plurality of cylinders, individual operating mechanisms for said bows each including a reciprocable element mounted in one of the cylinders, air pressure and vacuum tanks, a spring-held vertically-movable member having a port to establish communication between said tanks and the cylinder, a slide valve actuated by said member to alternately open and close communication between the respective tanks and said cylinders through said port, operating means for each of said members including a pivoted element, a movable perforated web, said pivoted elements being adapted to be received in certain of the perforations of said web and actuated by the web whereby the vertically movable members are selectively actuated and the respective bows operated.

8. The combination with a stringed musical instrument, of bows operating upon the respective strings of the instrument, pneumatically actuated means for independently operating said bows, fingers to engage the respective strings of the instrument, vacuumactuated means normally holding the fingers out of engagement with the strings, and means for selectively controlling the pneumatically-actuated bow-operating mechanisms and also selectively destroying the vacuum whereby the respective fingers are released to permit of the operation of the finger mechanisms to move the fingers into engagement with the strings.

I 9. The combination with a stringed musical instrument, of bows engaged upon the respective strings of the instrument, pneumatically actuated mechanisms for independently operating the bows, a plurality of fingers for engagement with the strings of the instrument, independent means for operating said fingers each normally held against operation by an air vacuum, a tracker board having air ducts therein through which the vacuum may be destroyed, and a web having perforations to register with certain of the air ducts whereby the individual operating means are permitted to operate by the destruction of the vacuum to move the fingers into engagement with the strings, said web being provided with additional means for controlling selectively the operation of the bows.

10. The combination with a stringed musical instrument, of bows engaged upon the respective strings of the instrument, pneumatically controlled individual operating mechanisms for the bows, a plurality of fingers adapted to engage the strings of the instrument, independent means for operat ing the respective fingers each normally held against operation by a vacuum, a tracker board provided with air ducts through the medium of which the air vacuum may be destroyed, and a web provided with-two series of perforations, one of which is adapted to register with certain of the air ducts in the tracker board to destroy the vacuum of the individual finger controlling mechanisms and permit the fingers to engage upon the respective strings, and the other series of perforations in said web controlling selectively the actuation of the bow operating mechanisms.

11. The combination with a stringed musical instrument, of bows operating upon the respective strings of the instrument, pneumatically actuated means for operating each bow, fingers to engage the respective strings, means urging the fingers into engagement with the strings, pneumatically actuated means normally holding the fingers in an inoperative position, and means for con trolling the operation of the pneumatically actuated means for the respective bows and also controlling the operation of the pneumatically actuated means for the fingers, whereby the individual fingers move into engagement with the respective strings of the instrument.

12. The combination with a stringed musical instrument, of bows engaging the respective strings, a series of cylinders, a piston in each cylinder, string-engaging fin gers, means urging the fingers into engagement with the respective strings, means 0peratively connected to each piston for actuating the respective fingers, means for creating a vacuum in each cylinder to actuate said latter means and move the associated finger to an inoperative position, a tracker board having air ducts, tubes connecting the respective cylinders to the air ducts, a web provided with a group of openings adapted to register with the respective air ducts and destroy the vacuum in the respective cylinders, whereby the fingers are permitted to engage the strings of the instrument, and pneumatically actuated mech anisms for independently operating said bows, each including a web-actuated element, said web having a second group of perforations to receive the web-actuated elements of the several bow-operating mechanisms, whereby the latter are actuated in the movement of the web to independently operate the bows.

In testimony whereof I hereunto affix my signature in the presence of two witnesses.

LEDRA M. LAWTON.

Witnesses LEE B. WARD, CARRIE L. WARD.

Copies 0t this patent may be obtained for five cents each, by addressing the flommissiener of I'atents, Washington, D. G. 

